haevey



(No Model.)

H. A. HARVEY.

MACHINE FOR ROLLING THE THREADS OF WOOD SCREWS.

No. 284,633. Patented Sept. 11, 18-83.

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UNITED STATES PATENT OFFICE.

HAYIVARD A. HARVEY, OF ORANGE, NEW JERSEY.

MACHINE FOR ROLLING THE THREADS OF WOOD-SCREWS.

SPECIFICATION forming part of Letters Patent No. 284,633, datedSeptember 11, 1883.

' Application filed May as, 1883. (No model.)

To aZZ whom it may concern:

Be it known that I, HAYWARD A. HARVEY, of Orange, New Jersey, haveinvented an Improvement in Machines for Rolling the Threads ofWood-Screws, of which the following is a specification.

My invention relates to the class of screwthreading machines in whichthe thread is formed by causing the blank to be rolled along the curvedface of a stationary die having suitably inclined ribs by the actionupon it of a cylindrical rotating die having correspondingoppositely-inclined ribs formed upon its face; and my invention consistsin giving to the stationary die the capacity of yielding in a directionperpendicular to the axis of the rotating die. The desirableness ofgiving to the stationary die this yielding capacity arises from the factthat the ordinary iron'wire of commerce is now drawn in suchextremelengths that the opposite ends of a coil exhibit considerabledifferences in diameter. By making my concave-faced die yielding andsupporting it by powerful springs I am enabled to roll screwthrcads uponblanks of varying sizes without crushing the larger blanks and withoutthe clogging of the machine, which has heretofore sometimes been causedby the presence of an unusually large blank.

The accompanying drawings, representing the parts of a machine forrolling screwb1anks which are necessary to exhibit the application of myinvention, areas follows:

Figure 1 is a top view, showing one of the cylindrical rotating dies andthe concave-faced yielding die. Fig. 2 is a vertical section'through theline a" m 011 Fig. l.

I have not deemed it necessary to show in the drawings any more than apair of the dies employed, as the machine for rolling screwblanks isfully described in my Patent No. 223,730, of January 20, 1880.

The rotating cylindrical die A is affixed to the upper end of thevertical shaft A in the same horizontal plane with the usualconcavefaced die, B. The concave-faced die B rests upon the horizontalbed or table 0, andis tapped in the center of its convex side toreceive' the check-bolt D, the shank of which is inserted through theconcave flange E, which is cast upon or otherwise fastened to the bed ortable upon which the concave die rests. The object of the boltD is tolimit the range of movement of the die B toward the rotating die. Theposition of thedie B with relation to the rotating die is determined bymeans of the adjusting-screws F and F, for which holes are tappedhorizontally through the flange E in directions which are radial inrelation to the rotating cylindrical die. The inner ends of these screwsbear upon the convex sides of stiff curved spring-plates G and G, theends of which bear, respectively, either upon the convex face of the dieB, or, if desired, upon other curved spring-plates, g g, interposedbetween the convex face of the die B and the spring-plates G G. Byturning in the adjusting-screws F F the die B may be moved toward therotating die until the under side of the head of the screw-bolt D bringsup against the exterior face of the flangeE.

The machine is operated in the same way as my machine shown anddescribed in my Patent No. 223,730, of January 20, 1880, with respect tothe method of feeding the blanks to it and the operations which itperforms upon I the blanks; but by means of my present invention thedies are adapted to roll screwthreads upon blanks which may varysensibly in diameter. To that end-I make the springs which I havedescribed sufficiently stiff to hold the curved die firmly enough toenable the ribs upon its face to impress the grooves of the desireddepths in the body of the blank, while at the same time, if a largeblank should get into the machine, the springs will yield slightly, andthus the large blank will go through the machine and have the threadformed upon itsbody without either being crushed or stopping themachine.

I claim as my invention 1. In that class of screw-threading machines inwhich a blank'is made by the action of a rotating cylindrical die toroll across the concave face of a stationary die, mechanism,substantially as herein described, whereby the concave die is given thecapacity of yielding in a plane perpendicular to the axis of rotation ofthe rotating cylindrical die, as and for the purpose set forth.

drical die A and the concave-faced die B,

2. In combination with the rotating cylin having the capacity ofhorizontal movement I suitable perforation in the flange E, incombitoward and from-the rotating die, the adj ustnation with the adjusting-screwsF and F and ing-serews F and F, inserted horizontally thesprings interposed between the inner ends through the flange E; andsuitably curved of the adjusting-screws and the concave-faced 5spring-plates interposed between the ends of die, as and for the purposeset forth.

the adjusting-screws F and F and the convex 4 face of the dieB, as andfor the purpose set HARVEY forth. Vitnsses:

3. The concave-faced die 13, provided with E. H'. VVILLIAMs, 10 thecheek-screw D, loosely inserted through a R. O. HOWES.

